Ask HN: How do you organize your notes and ideas?

I have a big pile of files (text, pdf, images, tars, zips, all kinds of stuff) that contain ideas, concepts, software prototypes, sketches and stuff like that ... and it just sits there on my disk. I want to find whats in there, but can not motivate myself to organize it manually.

Are there any tools (offline, desktop) that allow me to search these various kinds of filetypes fast (!) and that do not require me to enter some "ecosystem" of "personal information management"? Maybe even with the possibility to reorganize the information virtually, without changing the actual files. Open source (GPL or similar) software preferred!

What do you use for this task?